Silica powder, silica container, and method for producing the silica powder and container

Technical Field

The present invention provides a silicon dioxide container and method of manufacturing the same, the container is of silicon dioxide with silicon dioxide as a main component; and to provide a container for manufacturing such a silicon dioxide of the silicon dioxide powder and method of manufacturing the same.

Background Art

Silica glass, is used as a large-scale integrated circuit (LSI) projection exposure apparatus for manufacturing (lithographic apparatus) of a lens, prism, or lighthood TFT substrate for display, lamp tube, window material, deflector plate, the cleaning container semiconductor industry, such as silicon dioxide semiconductor melt container. However, these of silica glass as a raw material, it is necessary to adopt the expensive silicon tetrachloride compounds, but also, because the silicon dioxide glass melting temperature or processing temperature is very high, approximately 2000 the [...] , therefore, energy consumption is large and the cost is very high. Therefore, since the earlier, a variety of proposed manufacturing method of silica glass.

For example, in Patent literature 1 in, discloses a method, is the silane oxide (silicon   alkoxide) water decomposition to become silicon dioxide sol, then the its gelation and become wet gel, and through the drying and become dry gel, through high-temperature roasting to get method of transparent silica glass body (the sol-gel method). Also, in Patent literature 2 in, discloses a method, the silica sol solution is from, its containing tetra methoxy silane or tetra ethoxy silane and the silicon dioxide particles, the mixed solution of silica sol a, sol-gel process of obtaining transparent silica glass method. Also, in Patent literature 3 in, discloses a silane oxide and silicon dioxide as the main raw material glass microparticle, to manufacture of transparent, in the manufacturing method of silica glass, for the 200 [...] -less than 1300 the the [...] of within the range of heat treatment, is carried out in an oxygen-containing environment, and then the temperature in the hydrogen-containing gas environment to 1700 the above [...] the heating processing, and in the aforesaid 2 between the heating treatment, a heat treatment for decompressing the environment. However, these previous the sol-gel method, the manufacturing of the silicon dioxide glass, not only in the initial period of the size accuracy or subsequent high temperature when in use, problems with the heat resistance, and are not cheap in cost.

Also, in Patent literature 4 in, discloses a kind of at least 2 kinds of different silica glass particles, for example, the silica glass powder and the silicon dioxide glass particles is made by mixing an aqueous suspension, then pressure forming and in the high-temperature sintering under containing silica complex obtained by the method (grouting forming method; slip   casting   method). Also, in Patent literature 5 in, discloses a method, the first (the slurry injection) mixed solution, containing the same 100 the following   m the size of the silicon dioxide glass particles and 100 the above   m the size of the silicon dioxide glass particles, and the mold frame by injection molding, followed by drying, sintering, to manufacturing non-transparent silica glass composite material. However, these previous grouting method, or sintering process in the drying process, large shrinkage of the molded body, unable to produce high size accuracy of the thickness of the glass body of silicon dioxide.

So, the above-mentioned silica glass as the method of manufacturing a molded article, have their own problems. Therefore, LSI used as the silicon single crystal (element) of the crucible for manufacturing method for producing silicon dioxide, is to adopt such as Patent document 6 and Patent document 7 the method of manufacturing. These method, the rotation in the carbon molding frame, inputs by the hyper-high-purity chemical-treated quartz powder or synthetic cristobalites (cristobalite) after forming fanner, the carbon electrode and pressed in from the upper part to the carbon electrode electrified, which produce the electric arc discharge, to make the environmental temperature is raised to the melting temperature region (presumed the 1800-2100 [...] left and right) and make the quartz powder melting, sintering method.

However, these manufacturing methods, since the use of ultra-high purity quartz raw material powder, therefore, there will be the problem of high costs. Also, because manufacturing of silicon dioxide has been dissolved in the crucible are not pure object gas, therefore, in use, when the silicon single crystal silicon dioxide for the growth crucible, will produce and discharge gas, a single-crystal silicon of these be mixed with air bubbles, and is referred to as empty or pinhole such a defect and the like, and in; the cost of manufacture and the problems on the quality of the crystalline silicon. Also, at the time of pulling up silicon single crystal with low etch the silicon melts the fluid -resistant, the silicon dioxide of the crucible from the durability problem.

In Patent literature 8 in, shown the silicon dioxide of the crucible for pulling up silicon single crystal to improve the resistance method of etching the silicon melts the fluid. In Patent literature 8 in, in the silica glass crucible shown in the inner surface of the crystallization accelerator to the effect of the dopant. As a crystallization accelerator, shown the element of group IIA metal element mg initial, Sr, Ca, Ba, and IIIA metal Al. However, in Patent document 8 shown in a silica glass crucible, the inner surface of the crucible portion and non-fully of gas bubble-free transparent silica glass layer, but contains various doping element uniform dissolving the residual particles and small bubbles. Therefore, in pulling a silicon single crystal, sometimes containing silicon dioxide particles of foreign matter will be empty and the defect or a pinhole and the like.

In Patent literature 9 in, shown the silicon dioxide of the crucible for pulling up silicon single crystal of the inner surface portions of the bubble so as to reduce in the silica glass, and inhibiting the silicon dioxide in the use of the expansion of the bubble of the crucible. In Patent literature 9 in, shown through the silicon dioxide of the crucible contains the concentration in the raw 5 × 10¹⁷ -3 × 10¹⁹ molecular/cm³ hydrogen of, and can inhibit under the high-temperature, under reduced pressure occurring at the time of pulling up silicon single crystal of the inner surface of the crucible the bubble expansion. However, this kind of method, at the time of pulling up silicon single crystal is still low, etching the silicon melts the fluid -resistant, the silicon dioxide have a problem on the durability of the crucible.

Literature of the prior art

Patent literature

Patent literature 1: Japanese extra Kaiping 7-206451, the

Patent document 2: Japanese extra Kaiping 7-277743, the

Patent literature 3: Japanese extra Kaiping 7-277744, the

Patent literature 4: Japan opens especially 2002-362932, the

Patent literature 5: Japan opens especially 2004-131380, the

Patent literature 6: Japan extra fair 4-22861, the

Patent literature 7: Japan extra fair 7-29871, the

Patent document 8: Japan extra Kaiping 8-2932, the

Patent document 9: Japan opens especially 2007-326780, the

Content of the invention

Subject to be solved by the invention

The invention is based on the problem of the development of, its purpose is to provide a method of manufacturing silicon dioxide container and the silicon dioxide container, the manufacturing method is to use a silicon dioxide powder of the main component as the main raw material, and with high size accuracy and low cost to produce a kind of silicon dioxide as a main component silicon dioxide container, the silicon dioxide container, the inner wall of the containing substantially no air bubbles is large and the thickness of a transparent silica glass layer, and also under the high temperature with high durability; and to provide a kind of silicon dioxide powder and its manufacturing method, the silicon dioxide powder in order to make such a silicon dioxide container.

Means of solving the subject

The invention, in order to solve the above-mentioned problem, provides a silicon dioxide powder, is used for the container and making the silicon dioxide of the silicon dioxide powder, characterized in that the particle size (particle   size) the 10-1000  m, the concentration of total 50-5000 Ca PPM (wt. ppm) by weight of the, Sr, Ba, and under the vacuum heating to 1000 the sundries of hydrogen when [...] for 3 × 10¹⁶ -3 × 10¹⁹ molecular/g.

If that is the case the silicon dioxide powder, the particle size thereof is 10-1000 the  m, the concentration of total 50-5000 initial weight of the metal element Ca PPM, Sr, Ba, and as the concentration of hydrogen in the vacuum heating to 1000 the sundries of hydrogen when [...] for 3 × 10¹⁶ -3 × 10¹⁹ molecular/g, and the silicon dioxide powder, is used as the raw materials for manufacturing silicon dioxide container, the use of silicon dioxide in the container under high temperature, the height of the can be obtained is not a pure substance, such as diffusion preventing effect and the durability, in use and can effectively inhibit the occurrence of bubbles in the portion of the silicon dioxide powder.

This occasion, the silicon dioxide powder, more preferably that contains the concentration 10-100 Al PPM of the weight.

In this way, in the adoption of the silicon dioxide powder containing concentration 10-100 Al PPM of the weight of the manufactured by silicon dioxide container, the Turkish an alkali such as Ba metal element better uniformly dissolved.

Also, more preferably as: aforesaid containing the concentration of Ba is 100-1000 weight PPM, and the aforesaid vacuum lower heating to 1000 the sundries of hydrogen when [...] for 5 × 10¹⁶ -5 × 10¹⁸ molecular/g, Li contained in the silicon dioxide powder, Na, K plurality of concentration in the 60 weight ppb (wt .ppb) the following.

Silicon dioxide powder, if this is the case of the hydrogen molecule concentration Ba sundries and Li, Na, the concentration of K, in the manufactured silicon dioxide container, can be more assured high degree of impurity diffusion preventing effect and the durability, and the like, takes place in the bubble can be effectively suppressed, but also, the inner wall of the container can be of the silicon dioxide with sufficient high purity.

Also, the present invention provides a manufacturing method of silicon dioxide powder, is used for manufacturing silicon dioxide container manufacturing method of the silicon dioxide powder, characterized in that comprising: the production process, by making the same of the silicon dioxide powder, the particle size of the powder for the 10-1000  m, and containing Ca, Sr, at least one of Ba; input process, the aforesaid powder in the heating furnace with the air tightness of the; reduced pressure exhaust process, in the aforesaid heating furnace exhaust to 10³ Pa the following; a heat treatment process, its containing 10-100 volume % (vol. %) Of hydrogen in the gas introduced into the heating furnace, the hydrogen is contained in the pressure of the gas environment is 1-100kgf/cm², as the temperature of the the 200-800 [...] ; and cooling process, the hydrogen-containing gas in the aforesaid heating furnace pressure of the environment in the sustained 1kgf/cm² the above, and the aforesaid powder cooling to 50 the [...] the following.

If that is the case of the manufacturing method of the silicon dioxide powder, can create a silicon dioxide powder, is used as the raw materials for manufacturing silicon dioxide container, the powder in the high temperature silicon dioxide of the container, can obtain a high degree of impurities, such as diffusion preventing effect and the durability, in use and can effectively inhibit the occurrence of bubbles in the portion of the silicon dioxide powder.

This occasion, in the aforesaid powder, more preferably in order to contain the total concentration is 50-5000 weight of PPM Ca, Sr, Ba.

If the concentration of powder in the containing such Ca, Sr, Ba, the manufactured silicon dioxide container, can be more assured high degree of impurity diffusion preventing effect and the durability, and the like, also, takes place in the bubble can be sufficiently suppressed.

Also, in the aforesaid powder, more preferably for separately containing concentration is 100-1000 PPM of the weight of the Ba, and containing concentration is 10-100 Al PPM of the weight.

The powder in such respectively containing the concentration of Ba, Al, the silicon dioxide container is manufactured, can be more assured high degree of impurities, such as diffusion preventing effect and the durability. Also, by containing the Al, such as the initial Ba metal element can be more uniformly dissolved, thereby more effectively inhibit the inner wall of the container occurs in the silicon dioxide in the bubble.

Also, the present invention provides a silicon dioxide container, characterized in that with: matrix, with rotary symmetry thereof, with silicon dioxide as a main component, and containing air bubbles at least partly on the periphery; and the inner layer, which is formed in the base body on the inner surface of, and is a transparent silica glass; and, the aforesaid substrate Li, Na, the total of K concentration is 50 weight PPM the following; the aforesaid inner layer, containing a total concentration is 50-5000 weight of PPM Ca, Sr, Ba, and the thickness of the cut 10 mm sample of the optical wavelength of 600 nm the light transmittance was 91.8-93.2%.

If it is such a silicon dioxide container, even if the low-cost, and has sufficient silicon dioxide for the uniformity of the temperature of the container, can also be at high temperature when in use, the height of the inner wall is not pure material diffusion preventing effect and the durability, and the like, and can effectively inhibit the occurrence of bubbles in the inner wall. As a result, silicon dioxide container can be suppressed in the inner wall of the air bubble, the adverse effects caused by the stored object. Furthermore, the value of the light transmittance, its reflected in the glass bubble of uniform solubility and doping elements.

This occasion, the inner layer, more preferably is to contain concentration 10-100 Al PPM of the weight.

In this way, if the concentration in the inner layer 10-100 Al PPM of the weight of, the Turkish an alkali such as Ba metal element can be more uniformly dissolved, thereby more effectively inhibit the inner wall of the container occurs in the silicon dioxide in the bubble.

Also, the inner layer, more preferably is Li, Na, K plurality of concentration in the 60 the following ppb by weight, the concentration of Ba is 100-1000 weight PPM, and the inner layer cut from a sample in the vacuum heating to 1000 the hydrogen [...] the extention of the quantity of the not full 1 × 10¹⁶ molecular/g.

In this way, if the inner layer contains alkali metal element Li, Na, K plurality of concentration in the 60 the following ppb by weight, the concentration of the Ba 100-1000 weight PPM, and the inner layer cut from a sample in the vacuum heating to 1000 the hydrogen [...] the extention of the quantity of the not full 1 × 10¹⁶ molecular/g, can be more assured high degree of impurity diffusion preventing effect and the durability, and the like, takes place in the bubble can be effectively suppressed, but also, the inner wall of the container can be of the silicon dioxide with sufficient high purity.

Also, the present invention provides a method of manufacturing silicon dioxide container, characterized in that

Container for manufacturing silicon dioxide, the silicon dioxide container has: a substrate, having rotational symmetry, with silicon dioxide as a main component, and containing air bubbles at least partly on the periphery; and the inner layer, which is formed in the base body on the inner surface of, and is a transparent silica glass;

Wherein method of manufacturing the silicon dioxide container, ready to silicon dioxide the powder comes as in order to form the aforesaid inner layer of the raw material powder, and using the same raw material powder for forming the inner layer of the silicon dioxide powder, in the aforesaid inner surface of the base material forming the inner layer, the silicon dioxide powder, the particle size thereof is 10-1000 the  m, the concentration of total 50-5000 weight of PPM Ca, Sr, Ba, and under the vacuum heating to 1000 the sundries of hydrogen when [...] for 3 × 10¹⁶ -3 × 10¹⁹ molecular/g.

If this is the case for at least the use of particle size the 10-1000  m, the concentration of total 50-5000 weight of PPM Ca, Sr, Ba, and as the concentration of hydrogen in the vacuum heating to 1000 the sundries of hydrogen when [...] for 3 × 10¹⁶ -3 × 10¹⁹the powder comes molecular/g forming the inner layer of silicon dioxide of the silicon dioxide of the method for manufacturing of the container, the container of the manufactured silicon dioxide, at high temperature when in use, the height of the can be obtained is not a pure substance, such as diffusion preventing effect and the durability, and can effectively inhibit the inner wall portions of the container in the silicon dioxide in the bubble.

Also, silicon dioxide of this invention method of manufacturing container, can include:

The production process, the particle size of producing the same 10-1000 the powder   m, as a raw material of the substrate in order to form the aforesaid, Li the powder, Na, K of the total concentration is 50 weight PPM the following, and the particle size the 10-1000  m;

The temporary molded body made of the process, with rotary symmetry on one side thereof, and formed with a pressure distribution on the inner wall of the hole of the outer frame can be rotated, while the raw material powder for forming the matrix to be introduced into the external mold capable of reducing pressure to the inner wall of the frame, and corresponds to the capable of reducing pressure the inner wall of the outer frame, temporarily formed into a predetermined shape, the temporary molded body of the substrate;

The inner layer of the temporary molded body made of the process, the aforesaid capable of reducing pressure on one side of the outer frame to be rotary, while the aforesaid ready for the inner layer of the raw material powder for forming the silicon dioxide powder to be introduced into the temporary substrate on the inner surface of the molded body, and corresponds to the base of the inner surface of the temporary molded body, temporarily formed into a predetermined shape, and to make the inner layer of the temporary molded body; and

Forming the base and the inner layer of the process, the aforesaid capable of reducing pressure through the die formed by the frame with the hole through the pressure, will the base and the inner layer of the temporary molded body, temporarily from the base of the peripheral side of the molded body to the degassing (degas), and through discharge heating melt from the base and the inner layer of the inner side of the temporary molded body to be heated, so that the the base of the peripheral part of the temporary molded body into a sintered body, and the base of the inner portion of the molded body and the aforesaid inner layer of the temporary molded body into a molten glass body, to form the base and the inner layer.

Also, silicon dioxide of this invention method of manufacturing container, can include:

The production process, the particle size of producing the same 10-1000 the powder   m, as a raw material of the substrate in order to form the aforesaid, Li the powder, Na, K of the total concentration is 50 weight PPM the following;

The temporary molded body made of the process, with rotary symmetry on one side thereof, and formed with a pressure distribution on the inner wall of the hole of the outer frame can be rotated, while the raw material powder for forming the matrix to be introduced into the external mold capable of reducing pressure to the inner wall of the frame, and corresponds to the capable of reducing pressure the inner wall of the outer frame, temporarily formed into a predetermined shape, the temporary molded body of the substrate;

Matrix forming process, through the aforesaid capable of reducing pressure the pressure of the outer frame for the decompression hole, the the base of the temporary molded product from the outer circumferential side to the degassing, and through discharge heating melt from the base of the temporary molded body at the inner side of the high-temperature heating, the the base of the peripheral part of the temporary molded body into a sintered body, and the inboard part of the molten glass is formed into a matrix; and

The process of forming the inner layer, one side of the same from the inner side of the base, spraying the prepared raw material for forming the inner layer of the silicon dioxide powder, while heating by electric discharge from the fusion process at the inner side of the high-temperature heating, and in the aforesaid matrix is formed on the inner surface of the inner layer.

This occasion, also can be the external mold capable of reducing pressure in the formed by the frame and of the degassing hole, one side of the process carried out to form the aforesaid inner layer.

Also, silicon dioxide of this invention method of manufacturing container, can include:

The production process, the particle size of producing the same 10-1000 the powder   m, as is used for forming the base of the raw material powder, the powder Li, Na, K of the total concentration is 50 weight PPM the following;

The temporary molded body made of the process, the raw material powder for forming the matrix to them with rotary symmetry of the inner wall of the outer frame, corresponding to the outer and to the inner wall of the frame, is formed into the specified shape for the time being, of the temporary molded body of the substrate;

The process of the matrix forming, heating the bottle through the discharge thereof, from the base of the temporary molded body at the inner side of the high-temperature heating, to form a substrate; and

The process of forming the inner layer, the inner side of the base from the same, ready for the aforesaid raw material for forming the inner layer of the silicon dioxide powder to be sprayed, while heating by electric discharge from the fusion process at the inner side of the high-temperature heating, and in the aforesaid matrix is formed on the inner surface of the inner layer.

In this way, in the present invention method of manufacturing the silicon dioxide in the container, and the substrate after forming the inner layer to be temporarily, can simultaneously heating two temporary have been packed into the body, also, the shaping and temporarily of the basal body and which forms a matrix after melting and sintering, raw material can also be sprayed (silicon dioxide powder) the inner layer and heating. Also, any one discharge heating procedure can also be carried out under the atmospheric pressure, can also be carried out under reduced pressure.

Also, the invention of the method of manufacturing silicon dioxide container, through the aforesaid discharge heating to the fusion process in the process of the at least one of the, containing the oxygen 1-30% and the volume of the inert gas formed by mixing the mixed environment.

In this way, if by the discharge heating fusion process in the process of the at least one of the, containing the oxygen 1-30% volume and the mixing of the inert gas environment, can be from the carbon electrode of the carbon particle to oxidation treatment and gas become CO or CO₂, to obtain carbon (C) microparticle less silicon dioxide container.

Also, the invention of the method of manufacturing silicon dioxide container, through the aforesaid discharge heating to the fusion process in the process of the at least one of, in the dew point temperature is set to the 10-10 the [...][...] and the setting temperature can be controlled within ± 1 within the scope of of [...] carried out under an air environment.

In this way, if by the discharge heating fusion process in the process of the at least one of, in the dew point temperature is set to the 10-10 the [...][...] and the setting temperature can be controlled within ± 1 within the scope of of [...] carried out under an air environment, notwithstanding is that the low cost can also be reduced in the container-silicon dioxide and moisture content of OH (H₂ O) amount.

Effect of the invention

The above-mentioned, if it is in accordance with the present invention the silicon dioxide powder, silicon dioxide is used for manufacturing the raw material for the inner layer of the container, the high temperature silicon dioxide of the container, can obtain a high degree of impurities, such as diffusion preventing effect and the durability, in use and can effectively inhibit the occurrence of bubbles in the portion of the silicon dioxide powder. Also, if it is in accordance with the manufacturing method of silicon dioxide powder of the invention, having such effect is capable of producing the silicon dioxide powder.

Also, if is the silicon dioxide container in accordance with the present invention, even if the low-cost, and have sufficient temperature uniformity of the silicon dioxide container, at high temperature when in use, by the height of the inner wall of the impurity diffusion preventing effect and the durability, and the like, and can effectively inhibit the occurrence of bubbles in the inner wall. As a result, silicon dioxide container can be suppressed in the inner wall of the air bubble, the adverse effects caused by the stored object.

Also, if it is in accordance with the present invention manufacturing method of the silicon dioxide container, the manufactured silicon dioxide container, at high temperature when in use, the height of the can be obtained is not a pure substance, such as diffusion preventing effect and the durability, and can effectively inhibit the inner wall portions of the container in the silicon dioxide in the bubble.

Description of drawings

Figure 1 is compend flowchart of the manufacturing method of silicon dioxide powder of the invention.

Figure 2 is compend profiles of said silicon dioxide of the present invention an example of the container.

Figure 3 is compend flowdiagram of said silicon dioxide container of the present invention one example of a method of manufacturing.

Figure 4 is compend flowdiagram of said silicon dioxide of the present invention method for manufacturing of the container of another example.

Figure 5 is compend profiles of the said silicon dioxide container of this invention for use in making an example of outline templet frame.

Figure 6 is compend profiles of the said silicon dioxide of the present invention for use in making of the container of another example of the frame.

Figure 7 is compend profiles of illustrative of the present invention in the in the manufacturing method of silicon dioxide container, matrix forming the temporary molded body of an example of the manufacturing processes.

Figure 8 is compend profiles of illustrative of the present invention in the in the manufacturing method of silicon dioxide container, the process of the matrix forming an example of a part of the (discharge heating molten front).

Figure 9 is compend profiles of illustrative of the present invention in the in the manufacturing method of silicon dioxide container, the process of the matrix forming an example of a part of the (discharge in heating fusion).

Figure 10 is compend profiles of illustrative of the present invention in the in the manufacturing method of silicon dioxide container, forming the inner layer an example of the manufacturing processes.

Figure 11 is compend profiles of illustrative of the present invention in the in the manufacturing method of silicon dioxide container, temporarily on the base body on the inner surface of the molded body of the temporary molded body forming the inner layer of the one example of the process.

Figure 12 is compend profiles of illustrative of the present invention in the in the manufacturing method of silicon dioxide container, the matrix of the inner layer of the temporary molded body and to discharge the temporary molded body is heated at the same time one example of the manufacturing processes.

Mode of execution

As mentioned above, previous silicon dioxide in the manufacture of the container, with a size accuracy, the problems of cost.

Also, together with, for example, single crystal silicon growth in silicon dioxide crucible, will be facing to the single crystal silicon mixing in the bubble, the container in the previous manufacturing method of the silicon dioxide of the silicon dioxide in the container, the air bubbles towards the stored object has released the problem of the adverse impact.

The present inventors, based on this review of the problem, the subject of and find the following.

First of all, the metal silicon is melted and crystalline silicon the crucible or boat for producing the silicon dioxide container, and the like, must have in the heating the high-temperature environment in the ones inside the container. Therefore, the silicon dioxide is that at least the 1st issue multiple structure of a container, the container is set on the outer side of a porous white opaque silica glass, and the container is set on the inner side of the thickness of the bubble and substantially colorless transparent silica glass.

Also, the subject 2nd, is to prevent the diffusion of the role of the pure product (not pure object shielding function). This is in order to inhibit silicon dioxide in the container object containing the impurities, contained in the container toward the silicon dioxide of the adverse effects of the contamination of the stored object.

For example, in manufacturing silicon single crystal silicon dioxide container containing the impurities of the metal element, for example, not only is an alkali metal element Li (lithium), Na (sodium), K (potassium), in particular Ti, Cr, Mn, Fe, Ni, cu, Zn, Zr, Mo, and W (tungsten), and is mixed in in (is introduced) of silicon, such as solar heat (solar power generation) the purposes of silicon element, the photoelectric conversion efficiency will be low. Therefore, in order to make the silicon dioxide containing pure not of the container will not spread to the way the silicon melts the fluid , to make the silicon dioxide to the inner surface of the container (glass ceramic) fine crystallization, prevent and which has the role of the proliferation of pure material. Also, as the silicon dioxide of the inner surface of the container part of the fine crystallization quality, but also to various crystalline size of fine, careful, such as the use of the crystallization layer of cristobalite.

Also, the subject 3rd, extremely dense cristobalite is through the silicon dioxide to the inner surface of the vessel to be fine crystallization, etching resistance by.

For example, when producing silicon single crystal, the composition of the silicon dioxide container (SiO₂) itself will melt into a molten liquid, therefore once mixins silicon crystallization in oxygen, such as will be caused in the silicon element for solar energy photoelectric conversion efficiency is low. Therefore, silicon dioxide the inner surface of the vessel, must have the characteristic of the silicon melts the fluid it is difficult to melt (the silicon melts the fluid -resistant etching), that is, similarly to the inner surface of the container to be fine crystallization.

And then, on the silicon dioxide surface layer in the container as a crystallization accelerator initial Ca metal elements (calcium), Cr (strontium), Ba (barium) is non-uniform doping, and containing in the inner surface layer on the occasion of fine bubbles, when in manufacturing silicon crystallization from the bubbles containing the gas, these released in dissolution to the silicon melts the fluid will, therefore be mixed with the air bubbles is produced by crystallizing silicon is known as the structure of the cavity or a pinhole defect. Therefore, 4th issue, is that the silicon dioxide surface layer portion in the container does not contain bubbles, so that the alkali the Turkish metal elements are uniformly dissolved, and the silicon dioxide glass is completely colorless and transparent, light transmittance is high and large thickness of the silicon dioxide glass layer.

As indicated above, the subject 5th, the invention must be in order to than previously obtained by the method of manufacturing high-purity single crystal silicon pulling of a crucible used for silicon dioxide container is more low-cost manner, at the same time solve the above-mentioned four technical problem.

The following, with reference to one side of the one side of the attached drawing in detail represents invention, but the invention is not limited to these descriptions. In particular suitable for application of the following major was cited as an example of the present invention, to carry out that silicon dioxide container (crucible solar grade) and its manufacturing method, the silicon dioxide container can be used as a solar cell (solar power generation, solar power generation) is the material of the container for the molten silicon metal, but this invention is not limited to this application, and to widely apply to the silicon dioxide as a principal component of silicon dioxide with rotary symmetry of the container.

Figure 2 is compend profiles of said silicon dioxide of the present invention an example of the container.

On the silicon dioxide of this invention the container 71, with rotary symmetry, its basic structure, is made up of a base 51, and the inner layer 56 a by.

The base body 51, has rotary symmetry thereof, with silicon dioxide as a main component. Also, the base 51, the outer peripheral side of the substrate 51a comprises gas bubbles, porous with the addition of a white, opaque, and on the inner peripheral side of the base body 51b, the typical is a semitransparent-transparent.

Also, the inner layer 56, which is formed on the substrate 51 on the inner surface of, and is a transparent silica glass.

And then, the substrate 51 Li of, Na, the total of K concentration is 50 weight PPM the following.

Also, the inner layer 56, containing a total concentration is 50-5000 weight of PPM Ca, Sr, Ba, and the thickness of the cut 10 mm sample of the optical wavelength of 600 nm the light transmittance was 91.8-93.2%, more preferably is 92.4-93.2%.

Furthermore, silicon dioxide container of the present invention, at least the surface of the base member 51 and the inner layer 56, and further contains these can also be of the layer.

If it is such a silicon dioxide container, is low cost, and have sufficient temperature uniformity. In other words, silicon dioxide container, through at least the outer peripheral side of the substrate 51a is designed in multiple porous opaque silicon dioxide body , and at least the inner layer 56 is substantially free of air bubbles and the thickness of transparent silica glass body, so the silicon dioxide container 71 in the high-temperature use, can improve the silicon dioxide container 71 the homogeneity of the temperature of the interior of the.

Also, the above-mentioned the inner layer 56 containing Ca, Sr, at least one of Ba, especially Ba, and the silicon dioxide container 71 in the 1400-1600 [...] high temperature use, and the cristobalite silica glass surface portion of the re-crystallization, the result, can prevent the silicon dioxide container 71 matrix 51 containing Na, K, Li the diffusion of the alkali metal element such as dissolution, also, can reduce the silicon dioxide container 71 the silicon melts the fluid processing of the stored object, such as metal, for the silicon dioxide container 71 caused by the inner surface of the etching.

Furthermore, in accordance with the present invention, the inner layer can effectively inhibit 56 occurs in the situation of air bubbles. As a result, can inhibit in silicon dioxide container 71 in the inner wall of the air bubble, the adverse effects caused by the stored object.

Furthermore, the inner layer 56 fully restrain bubble, and alkaline earth metal such as Ba elements are uniformly dissolved occasions, from the inner layer 56 is cut out of the thickness of 10 mm of the sample of the light wavelength of 600 nm the light transmittance was 91.8-93.2%, and then without air bubbles, and the alkaline earth metal is the light transmittance is 92.4-93.2%. The upper limit value of 93.2% silicon dioxide glass is the maximum value of the theoretical.

The inner layer 56 containing concentration is 10-100 weight aluminum PPM (Al), can and then additional impurities diffusion preventing effect, and the alkaline earth metal such as Ba more uniformly dissolved elements. Therefore, the silicon dioxide can be more effectively inhibit the inner wall of the container occurs in the situation of air bubbles.

Although it is not clearly Al used to prevent impurities in the metal element in the movement of the silicon dioxide glass, diffusion of the detailed mechanisms, however, according to the aluminum (Al) and silicon (Si) atoms of the substitution reaction of the atoms (substitution   reaction), its coordination number (coordination   number) of the different, so the Li⁺, Na⁺, K⁺ non-pure object, such as a cationic metal elements (cation) hold the silicon dioxide glass network charge-balanced this point, the adsorption can be estimated, the effect for preventing the diffusion of.

Consider Al atoms and Si atoms of the substitution reaction of the, has used to obtain the charge balance Ba²⁺ alkaline earth metal element, such as of the role of cationic also to be fixed, can be can be uniformly dissolved in the element such as Ba, through this point also can inhibit the bubble in the silica glass.

Also, more preferably, the inner layer 56 Li of, Na, each concentration of K is set as 60 the following ppb by weight, and silicon dioxide container 71, the contact portion with the stored object with sufficient high purity. Also, the inner layer 56 is of the concentration of Ba 100-1000 weight PPM, can be more assured high degree of impurities, such as diffusion preventing effect and the durability.

Also, more preferably to the inner layer 56 can be cut under the vacuum heating to 1000 the hydrogen [...] the extention of the quantity of the not full 1 × 10¹⁶ molecular/g, thereby effectively inhibiting bubble generation.

If the above-mentioned, silicon dioxide container 71 endosexine of the part (i.e., the inner layer 56), must, as far as possible does not contain any fine bubble. This reason, for example, in silicon dioxide container 71 molten metal in the feedstock, to a certain extent will be molten silicon dioxide etched endosexine of the container part, and the inner surface layer part containing fine air bubbles once, the gas in the bubbles will be streamed to the molten silicon, its result, for example, in solar energy by the occasion of the processing of the silicon wafer, the wafer produced is referred to as empty space or a pinhole, defect.

In order to make the silica glass contains no fine bubble, must manufacture silicon dioxide raw material powder, the containing (doping) in order to promote Ca alkaline earth metal element, Sr, such as Ba the elements of the crystallization, at the same time, we must make the its containing hydrogen (H₂). Specifically, the silicon dioxide powder, the particle size thereof is 10-1000 the  m, the concentration of total 50-5000 weight of PPM Ca, Sr, Ba, and under the vacuum heating to 1000 the sundries of hydrogen when [...] for 3 × 10¹⁶ -3 × 10¹⁹ molecular/g. More preferably is to make the its containing 100-1000 of weight and Ba PPM 5 × 10¹⁶ -5 × 10¹⁸ the hydrogen molecular/g.

Also, if these contain 10-100 Al PPM of the weight, an alkali such as Ba can be the more uniform the Turkish metal element dissolved.

In other words, the 50-5000 initial weight of the metal element Ca PPM, Sr, Ba (more preferably 10-1000 PPM of the weight of the Ba) and 3 × 10¹⁶ -3 × 10¹⁹ molecular/g (more preferably to 5 × 10¹⁶ -5 × 10¹⁸ molecular/g) the combination of the hydrogen molecule, the additive as a silicon dioxide powder, and, in addition and then adding 10-100 Al PPM of the combination of the weight, is to enable a crystallization accelerator is in the silica glass does not contain the fine bubbles of the extremely important. Previously these views there is no disclosure in the literature, but the present inventors first thought that and has to be empirical.

The crystallization accelerator of Ba is uniformly doped so that the melting of the silica glass does not contain fine bubbles mode is important. Although the detailed mechanism is not clear, but hydrogen molecule (H₂) oxygen molecules and molecules of larger radius (O₂) reaction, thus generating molecules of the water the smaller radius (H₂ O), diffusion is easy can be inferred, desorbing to silica glass and the effect of preventing the generation of air. Also, because of the smaller radius the molecules of the water molecule itself, and in the silica glass of the diffusion speed is fast, so that the almost will not remain in the silica glass can be achieved, even if some residual, also will not become the cause of forming bubbles. Also, in order to use at high temperatures when the silicon dioxide container, the surface of the silicon dioxide glass part to produce a large number of and uniform silicon dioxide fine crystallization, the crystallization accelerator is the Ba dissolved in silica glass is indispensable. Although the detailed mechanism is not clear, but using hydrogen containing environment in the heating treatment of the raw material powder of silicon dioxide of the silicon dioxide glass, the crystallization of the cristobalite, with the growth of the tendency of the deceleration. Therefore, if the hydrogen containing gas environment containing Ba in the heat treating of the silicon dioxide powder of the raw material powder adjustment, making the powder comes and uses this raw material silicon dioxide container, when the container is the use of silicon dioxide, can form slight and meticulous recrystallizaiton layer. The reasons for this: the hydrogen containing gas in the environment of the silicon dioxide powder to be heated in the after processing, the lack of oxygen and hydrogen molecules, powder institute the use of the silica glass made of some of the structure will be residual defect, the defect can be presumed that this structure would be appropriate, such as cristobalite reduction of crystal growth speed. Therefore, in order to form silicon dioxide container and the inner surface of the crystallization layer of the lamination, it is necessary to make the raw material powder in such a crystallization accelerator and containing Ba containing a high concentration of hydrogen.

In this way, the inner layer is used as a to 56 of the raw material powder for forming manufacturing method of silicon dioxide powder, specific description.

Figure 1 compend expressed on the manufacturing method of silicon dioxide powder of the invention.

First of all, as shown in Figure 1 of the (1) is shown, as a raw material base material comprised of silicon dioxide, which are made of the powder, the particle size thereof is 10-1000 the  m.

As the silicon dioxide of the container the material of the raw material powder for forming the inner layer, lists have high purity processing of natural quartz powder, natural manufacturing crystal powder, or synthetic party British powder, synthetic silica glass powder. If in order to reduce the bubble of the transparent layer used as a target, are preferably crystalline silicon dioxide powder, or, if in order to make high purity transparent layer used as a target, it more preferably is a synthetic powder. Particle size is more preferably for the 100-500  m. Purity, more preferably is silicon dioxide component (SiO₂) the 99.9999% by weight (wt. %) Or more, and alkali-metal Li, Na, K in the 60 the following ppb by weight, more preferably in the 20 the following ppb by weight. Also, more preferably Ti, V, Cr, Fe, Co, Ni, cu, Zn, Mo, W in their 30 ppb of the following weight, more preferably in the 10 ppb of the following weight.

Furthermore, as shown in Figure 1 of the (2) illustrated, the alkaline earth metal element as the above-mentioned raw materials added to the base material of silicon dioxide powder.

Specifically, the silicon dioxide powder containing calcium (Ca), strontium (Sr), barium (Ba) at least more than one kind of, more preferably to Ba. Containing the same as the method, the raw material powder is doped with hydrogen before the, dissolved in water or alcohol is selected the alkaline earth metal element in the chloride, acetate, nitrate or carbonate, and the like, made of such compound aqueous solution or alcohol solution and wherein the silicon dioxide raw material powder is impregnated in the drying and subsequent a specific element has been added to the powder.

Furthermore, in accordance with Figure 1 a (3)-(6) of the process shown, the hydrogen is added to the silicon dioxide powder.

Specifically, first of all, as shown in Figure 1 of the (3) is shown, the silicon dioxide powder, the air tightness of the inputs to a heating furnace (for example, with stainless steel sleeve (stainless   steel   jacket) electric furnace the air tightness of the) inner. Furthermore, as shown in Figure 1 of the (4) illustrated, in the heating furnace to reduced pressure exhaust. Subsequently, as shown in Figure 1 of the (5) shown in, set as the environmental gas 10-100vol / % hydrogen, 1-100kgf/cm² pressure (about 1-100 pressure, about 9.8 × 10⁴ -9.8 × 10⁶ Pa), 200-800     , more preferably for the 300-600 [...] , and for example 1-10 hours the heating processing. Subsequently, as shown in Figure 1 of the (6) as shown, the hydrogen containing gas continued to keep the pressure of the environment 1kgf/cm² the above, and lowering the temperature to the 50 [...] the following. Furthermore, in the hydrogen containing environment with hydrogen mix gas, is nitrogen (N₂), argon (Ar) or an inert gas, such as helium (He).

In this case, as shown in Figure 1 the (7) shown by the, related to the present invention is able to manufacture the silicon dioxide powder.

Furthermore, if the particle size of the inner layer is in the above-mentioned raw the 10-1000   m the scope of the right and left, in the 1000 under a vacuum of [...] H₂ almost completely discharged, therefore the 1000 under a vacuum of [...] H₂ sundries, is almost and the inner layer of the raw material powder for containing H₂ the amount of stock of the same.

Using such a silicon dioxide powder as a raw material powder, of the present invention to form on the silicon dioxide container 71 the inner layer 56. In other words, in the present invention, at least the use of silica as the powder comes in order to form the inner layer 56 of the raw material powder, in order to form the inner layer 56, the silicon dioxide powder, the particle size thereof is 10-1000 the  m, the concentration of total 50-5000 weight of PPM Ca, Sr, Ba, and under the vacuum heating to 1000 the sundries of hydrogen when [...] for 3 × 10¹⁶ -3 × 10¹⁹ molecular/g.

The following, specific description of the above-mentioned silicon dioxide container 71 method of manufacturing. In particular the sunlight power generation element can be used as the material of the metal silicon (Si) of the molten and single crystal the rowing motion uses container to use, and can be manufactured at a low cost silicon dioxide container (crucible solar grade) method of manufacturing, as an example for description.

Figure 3 on the silicon dioxide of the present invention that the container 71 one example of the method of manufacturing (1st embodiment) the outline of the.

First of all, as shown in Figure 3 of the (1) illustrated, ready to silicon dioxide particles, that is, raw material for the basal body 11 for raw material and the inner layer 12 (process 1).

Using the above-mentioned on the silicon dioxide powder of the present invention, as the raw material for the inner layer 12. Its manufacturing method such as the above-mentioned (for example, Figure 1 the illustrated method).

On the other hand, raw material for the basal body 11, is the invention relates to silicon dioxide container 71 (with reference to Figure 2) in that the basal body 51 of the main elements of the material.

Raw material for the basal body, for example, can be the silicon dioxide in the following manner and blocks, by making the whole grain, but is not limited to this way.

First of all, the diameter of 5-50mm the left and right of the natural silicon dioxide block (natural output of the crystal, quartz, silica, silica rock, stone, etc.), under the atmosphere environment the 600-1000 [...] in the area of the temperature of the, heating 1-10 hours. Furthermore, the natural silicon dioxide block in water, and drying is taken out after cooling. Through this processing, the to the use of the crusher, and the like to be crushed, the whole grain processing, however, can not carry out this heating quenching processing direct pulverizing treatment.

Furthermore, through the crusher, and the like of the natural silicon dioxide blocks are crushed, granulate, to get the particle size more preferably 10-1000 the  m, more preferably 50-500 the natural   m dioxide powder.

Furthermore, the natural dioxide powder , inputs to have the angle of inclination of the silica glass tube (rotary   kiln) in the bottom of, the furnace containing hydrogen chloride (HCl) is set to be inside or chlorine (Cl₂) environment, and through 700-1100 the heating [...] 1-100 hours, to carry out high-purity treatment. However, in high-purity products shall not be in use, can not carry out the high-purity chemical processing, is directly forward to the next processing.

After the above process of raw material for the substrate 11, the silicon dioxide is crystalline, silicon dioxide, however, in accordance with the purpose of use of the container, also can use amorphous silicon dioxide glass scrap (scrap) as a raw material for the basal body 11.

For host raw material powder 11 particle size, such as the above-mentioned, is preferably 10-1000 the  m, more preferably the 50-500  m.

Raw material for the basal body 11 of the silicon dioxide purity, more preferably to 99.99 weight % or more, more preferably 99.999% or more by weight. In particular, Li, Na, the total value of K, more preferably to 50 weight PPM the following. Also, if it is a silicon dioxide of this invention method of manufacturing container, even in case of using the raw material for the basal body 11 is silicon dioxide purity of 99.999% the following relatively low weight of the purity of the silicon dioxide container is manufactured by, can fully prevent also accommodate for the pure not pollute the stored object. Therefore, to more than in the past to low cost manufacturing a silicon dioxide container.

Furthermore, raw material for the basal body 11 in, and then, also to contain more preferably for 10-500 Al PPM the range of a weight.

Aluminum (Al), for example, can be through the nitrate, acetate, nitrate, carbonate or chloride form the aqueous solution or alcohol solution, and the like, and the inputs to these solution of silicon dioxide in the raw, wherein impregnating the obtained subsequent to drying.

Prepared in the manner described above for raw material for the basal body 11 the rear, then, as shown in Figure 3 the (2) in the, raw material for the substrate 11 used for forming of the lead-in to the rotary symmetry of the outer frame (process 2).

Figure 5 as a raw material for the substrate 11 to be temporarily forming an example outline templet frame , capable of reducing pressure and compend said cross section of the outer frame. Capable of reducing pressure of the outer frame 101, for example, from graphite and the like material, and has rotation symmetry. Also, capable of reducing pressure of the outer frame 101 of the inner wall 102, in order to distribute a pressure reduction with the hole 103 way is formed. Decompression hole 103, is connected to the pressure-reducing by passage 104. Also, in order to make the capable of reducing pressure of the outer frame 101 of the rotating shaft 106, and also with the passage 105 is connected with the, and can be in a vacuum. Furthermore, the decompression hole 103, more preferably is added with a porous filter (not shown).

Raw material for the substrate 11, capable of reducing pressure to the outer frame 101 of the inner wall 102, and the raw material for the substrate 11, can be reduced corresponding to the outer frame 101 of the inner wall 102 shape, for temporary shaping, and form the temporary molded body of the substrate 41 (with reference to Figure 7).

Specifically, the continued capable of reducing pressure on one side of the outer frame 101 rotating, the raw materials from an slowly (not shown) for host raw material powder 11 to capable of reducing pressure in the outer frame 101 of the inner wall 102, and utilize the centrifugal force to make the its forming to the container shape. Also, also can be through the plate-like mold frame from the inner side (not shown) is contacted with a rotary powder, and the base of the temporary molded body 41 thickness adjusting to a predetermined amount.

Also, raw material for the basal body 11 can be decompressed towards the outer frame 101 of the supply method, there is no particular limitation, for example, can be the metering screw and for stirring the hopper of the feeder. This occasion, in the filling to the hopper of the raw material for the basal body 11, to the stirring screw used for mixing, and on one side in order to supply the metering feeder to adjust while supply.

Furthermore, as shown in Figure 3 the (3) is shown, the capable of reducing pressure on one side of the outer frame 101 rotating, while the raw material for the inner layer 12 to the substrate of the temporary molded body 41 on the inner surface of, and corresponding to the matrix of the temporary molded body 41 of the inner surface, temporarily formed into a predetermined shape, and the temporary molded body to make the inner layer 46 (process 3).

With the above-mentioned matrix is basically used raw material powder 11 occasions of the way into the same. I.e., capable of reducing pressure the continued of the outer frame 101 rotating, slowly from the raw material powder raw material for an inner hopper 12 into the temporary molded body to the base body 41 on the inner surface of, and use of the centrifugal force to make the its forming to the container shape (with reference to Figure 11).

Furthermore, as shown in Figure 3 the (4) as shown, by a pressure reducing, matrix forming discharge heating melting method 51 and the inner layer 56 (process 4).

Specifically, as shown in Figure 12, capable of reducing pressure through the outer frame 101 is formed by the pressure-reducing hole 103 for decompression, the temporary molded body of the substrate 41 and the inner layer of the temporary molded body 46, the temporary molded product from the base body 41 on the outer peripheral side of the degassing, and through discharge heating fusion process of the temporary molded product from the substrate 41 and the inner layer of the temporary molded body 46 at the inner side of the heating. The substrate of the temporary molded body 41 to form an outer peripheral portion of the sintered body, and the base of the temporary molded body 41 of the inner part of the temporary molded body and the inner layer 46 into the molten glass, and forms a matrix 51 and the inner layer 56.

In order to form the base 51 and the inner layer 56 of the device, in addition to the above-mentioned with the rotation of the scene may be capable of reducing pressure of the outer frame 101 outer, is composed of a rotary motor (not shown), and as a discharge heating molten (also referred to as electric arc melting, arc discharge molten) of the heat source of the carbon electrode (carbon   electrode) 212, wire 212a, high voltage power supply unit 211, the cover 213 a and the like. And then, with constituent elements, in order to adjust the same from the inner layer of the temporary molded body 46 for supplying the inside of the environmental gas, such as, O₂ gas supply bottle 411, an inert gas supply bottle 412, mixed gas supply pipe 420, dehumidifying device 430, dew point thermometer 440, and the like.

The through the discharge heating and melting of the base 51 and the inner layer 56 the forming process, the oxygen-containing 1-30% and the volume of the inert gas formed by mixing the mixed environment. This occasion, from the carbon electrode can be of the carbon particle to oxidation treatment and gas become CO or CO₂, to obtain carbon (C) microparticle less silicon dioxide container.

Also, the dew-point temperature is set to the 10-10 the [...][...] and the setting temperature is controlled in the ± 1 the is in the range of [...] carried out under an air environment. This occasion, although low-cost silicon dioxide can also be reduced in the container and the content of moisture OH-(H₂ O) amount.

For example, as the matrix of the temporary molded body 41 and the inner layer of the temporary molded body 46 of the molten, sintering procedures, the carbon electrode 212 before between the beginning of energization, first of all, through the dehumidifying set first to a predetermined dew point temperature, and will contain O₂ gas and the mixed gas of the inert gas, the temporary molded product from the substrate 41 and the inner layer of the temporary molded body 46 to start supplying at the inner side of the. Specifically, as shown in Figure 12, from O₂ gas supply bottle 411 supply O₂ gas, from the inert gas supply bottle 412 supply the inert gas (for example, nitrogen (N₂), argon (Ar), or helium (He)), to be mixed and the mixed gas supply pipe 420, and the temporary molded product from the substrate 41 and the inner layer of the temporary molded body 46 at the inner side of the supply. Furthermore, symbol 510 of the arrow shown (outlined   arrow) of the outer frame that the flow direction of the mixed gas.

Also, dew-point temperature setting, can through appropriate dehumidifying device, and the like, the determination of the dew point temperature, the dew point of the thermometer can be appropriate. Although in fig. 12 in, expressed the dehumidifying device 430, dew point thermometer 440 are assembled in the mixed gas supply pipe 420 in such a manner, however, is not limited to this, and can also be the temperature of the dew point of the mixed gas is set to a predetermined range of value.

Also, at this time, at the same time more preferably is capable of reducing pressure to the outer frame 101 of the gas in. This ventilation, capable of reducing pressure through the outer frame 101 of the environment gas from the cover 213 discharged to the outside of the gap of the way. Symbol 520 is shown with arrow showing the outer frame of the flow direction of gas ventilated environment.

Furthermore, if the above-mentioned already adjusted under the state of the environment, capable of reducing pressure the continued of the outer frame 101, the temporary molded body containing body 41 and the inner layer of the temporary molded body 46, rotating at a certain speed, and start the degassing by vacuum pump (not shown), from the temporary molded body 41 on the outer side of, through the pressure-reducing hole 103, passage and 104,105 to carry out decompression, and energization to begin to the carbon electrode 212 between.

The carbon electrode 212 between the arc discharge (to symbol 220 shown) at the time, the temporary molded body of the substrate 41 and the inner layer of the temporary molded body 46 of the inner surface portion, the region to become the melting temperature of the silicon dioxide powder (presumed the 1800-2000 [...] left and right), and from the surface layer to begin to melt. If the surface layer part is fused, by degassing the vacuum pump of the vacuum generated by the vacuum increases (pressure rapidly reduced), then continuation of the raw material for the basal body 11 and the inner layer with raw material powder 12 containing the gas storage of degassing, and into a fused silica glass layer changes, will be carried out from the inner side to the outside. Also, it is important to the timing of the vacuum, an inner surface layer on the inner side of the container is a glass front, vacuum strength can not be carried out. This reason is that if a beginning of a strong vacuum, temporarily the inner side surface of the molded body because the filtering effect will be attached, the gas environment thick product not contained in fine particles of the pure substance. Therefore, initially the degree of vacuum of not too high, more preferably on the basis of the surface of the molten glass, and gradually strengthen vacuum pumping.

Furthermore, according to the is energized to continue the heating of the pressure and the vacuum pump, until all of the substrate thickness of the inner layer and the inner side of the left and right half of the molten, the inner layer 56 become transparent silica glass, the inner peripheral side of the basal body 51b become transparent to semi-transparent layer, the base 51 of the peripheral portion (the outer side of the left and right half of the remaining) 51a become white, opaque after sintering (Department of opaque layer) of silicon dioxide. reduced pressure , more preferably for 10⁴ Pa the following, more preferably 10³ Pa the following.

In this way, can make Figure 2 of the present invention shown in a silicon dioxide container 71.

Furthermore, if the latter, 2nd embodiment and then the inner layer forming processes to be once or more than twice, and the inner layer 56 can be by purity or add-ons different more than two transparent silica glass layer.

In the Figure 4 on the silicon dioxide of the present invention that the container 71 method of manufacturing another example of the (2nd embodiment) the outline.

In accordance with this embodiment of a silicon dioxide container 71 manufacturing method, basically according to the Patent document 6, 7 the content of the shown. However, the above-mentioned use of the present invention the manufacturing of the silicon dioxide powder, as is used for forming the inner layer 56 of the raw material powder (raw material for an inner 12).

First of all, as shown in Figure 4 the (1) illustrated, ready to silicon dioxide particles, that is, raw material for the basal body 11 for raw material and the inner layer 12 (process 1).

With this process the occasion of the above-mentioned 1st embodiment of the same.

Furthermore, as shown in Figure 4 the (2) in the, raw material for the substrate 11 used for forming of the lead-in to the rotary symmetry of the outer frame (process 2).

This process can be also of the embodiment with the above-mentioned 1st occasions to the same as. However, under reduced pressure without the necessary to discharge the heating and the like, can be used also as shown in Figure 6 of the outer frame of the 101 [...] , to replace the Figure 5 is shown an external mold capable of reducing pressure of the frame 101. In addition frame the 101 [...] , for example, from graphite and the like material, and has rotation symmetry. In order to make the outer frame with the 101 [...] the rotation axis of the rotation of the 106 [...] , and the inner wall of the 102 with no special [...] hole or the like.

Furthermore, as shown in Figure 4 the (3) as shown, by a pressure reducing, matrix forming discharge heating melting method 51 (step 3).

Specifically, as shown in Figure 8, Figure 9 is shown, capable of reducing pressure through the outer frame 101 is formed by the pressure-reducing hole 103 for decompression, the temporary molded body of the substrate 41, of the temporary molded product from the base body 41 on the outer peripheral side of the degassing, and through discharge heating fusion process of the temporary molded product from the substrate 41 at the inner side of the heating. The substrate of the temporary molded body 41 to form an outer peripheral portion of the sintered body, and the base of the temporary molded body 41 to form the inner part of the molten glass, and form the base body 51.

On the other hand, as shown in Figure 6, without the use of special pressure reducing the occasion of the outer frame 101 the when [...] , is not special to decompression, and through the discharge heating fusion process of the temporary molded product from the substrate 41 at the inner side of the matrix forming the high-temperature heating and 51.

The following, mainly by using capable of reducing pressure on one side of the outer frame 101 on one side of the substrate 51 in a manner of forming, however, the occasion of the normal pressure in the, other than by pressure can also be the same process to form the base body 51.

In order to form the base body 51 of the device, as shown in Figure 8, Figure 9 shows, in addition to the above-mentioned with the rotation of the scene may be capable of reducing pressure of the outer frame 101 (or can also be outline templet frame the 101 [...]) the outer, is composed of a rotary motor (not shown), and as a discharge heating molten (also referred to as electric arc melting, arc discharge molten) of the heat source of the carbon electrode (carbon   electrode) 212, wire 212a, high voltage power supply unit 211, the cover 213 a and the like. Furthermore, with, its in order to adjust the temporary molded product from the matrix for supplying the inside of the environmental gas, such as, O₂ gas supply bottle 411, an inert gas supply bottle 412, mixed gas supply pipe 420, dehumidifying device 430, dew point thermometer 440, and the like.

Through this discharge heating melting method of the base 51 the forming process, the oxygen-containing 1-30% and the volume of the inert gas formed by mixing the mixed environment. This occasion, from the carbon electrode can be of the carbon particle to oxidation treatment and gas become CO or CO₂, to obtain carbon (C) microparticle less silicon dioxide container.

Also, the dew-point temperature is set to the 10-10 the [...][...] and the setting temperature is controlled in the ± 1 the is in the range of [...] carried out under an air environment. This occasion, although low-cost silicon dioxide can also be reduced in the container and the content of moisture OH-(H₂ O) amount.

For example, the temporary molded body as the matrix 41 of the molten, sintering procedures, the carbon electrode 212 before between the beginning of energization, first of all, through the dehumidifying set first to a predetermined dew point temperature, and will contain O₂ gas and an inert gas are mixed and the mixed gas, the temporary molded product from the substrate 41 to start supplying at the inner side of the. Specifically, as shown in Figure 8, from O₂ gas supply bottle 411 supply O₂ gas, from the inert gas supply bottle 412 supply the inert gas (for example, nitrogen (N₂), argon (Ar), or helium (He)), to be mixed and the mixed gas supply pipe 420, and the temporary molded product from the substrate 41 at the inner side of the supply. Furthermore, symbol 510 shown in the arrow showing the outer frame of the flow direction of the mixed gas.

Also, dew-point temperature setting, can through appropriate dehumidifying device, and the like, the determination of the dew point temperature, the dew point of the thermometer can be appropriate. Although in fig. 8, diagram 9 in, expressed the dehumidifying device 430, dew point thermometer 440 are assembled in the mixed gas supply pipe 420 in such a manner, however, is not limited to this manner, also can be through dehumidifying the mixed gas set to a dew point temperature of a predetermined range of value.

Also, at this time, at the same time more preferably is capable of reducing pressure to the outer frame 101 of the gas in. This ventilation, capable of reducing pressure through the outer frame 101 of the environment gas from the cover 213 discharged to the outside of the gap of the way. Symbol 520 is shown with arrow showing the outer frame of the flow direction of gas ventilated environment.

Furthermore, if the above-mentioned already adjusted under the state of the environment, capable of reducing pressure the continued of the outer frame 101, the temporary molded body containing body 41, rotating at a certain speed, and start the degassing by vacuum pump (not shown), from the temporary molded body 41 on the outer side of, through the pressure-reducing hole 103, passage and 104,105 to carry out decompression, and energization to begin to the carbon electrode 212 between.

The carbon electrode 212 between the arc discharge (to symbol 220 shown) at the time, the temporary molded body of the substrate 41 of the inner surface portion, the region to become the melting temperature of the silicon dioxide powder (presumed the 1800-2000 [...] left and right), and from the surface layer to begin to melt. If the surface layer part is fused, by degassing the vacuum pump of the vacuum generated by the vacuum increases (pressure rapidly reduced), then continuation of the raw material for the basal body 11 containing the gas storage of degassing, and into a fused silica glass layer changes, will be carried out from the inner side to the outside. Also, it is important to the timing of the vacuum, an inner surface layer on the inner side of the container is a glass front, vacuum strength can not be carried out. This reason is that if a beginning of a strong vacuum, temporarily the inner side surface of the molded body because the filtering effect will be attached, the gas environment thick product not contained in fine particles of the pure substance. Therefore, initially the degree of vacuum of not too high, more preferably is based on the surface of the molten glass, and gradually strengthen vacuum pumping.

Furthermore, according to the is energized to continue the heating and according to the pressure of the vacuum pump, all until the matrix of the inner side of the left and right half of the thickness of the melt, the inner peripheral side of the basal body 51b become transparent to semi-transparent layer, the base 51 of the peripheral portion (the outer side of the left and right half of the remaining) 51a become white, opaque after sintering (Department of opaque layer) of silicon dioxide. reduced pressure , more preferably for 10⁴ Pa the following, for better 10³ Pa the following.

Furthermore, as shown in Figure 4 the (4) as shown, one side of from the base 51 the inner side of the of, spraying is used for forming the inner layer of the raw material powder is silicon dioxide powder, while heating by electric discharge from the fusion process at the inner side of the high-temperature heating, the base 51 forming the inner layer on the inner surface 56 (process 4).

Furthermore, this process can be repeated also 4, different or additive in a purity of more than two transparent silica glass layer to form the inner layer 56.

With reference to Figure 10, shows that in order to form an inner layer 56 of the method.

The base 51 forming the inner layer on the inner surface 56 of the device, the same with the aforesaid process, with rotary scene is composed of rotatable and capable of reducing pressure of the outer frame 101, rotary motor (not shown), and the raw material to an 303 (into a in order to form an inner layer 56 raw material for the inner layer of 12), the screw used for mixing is 304, metering feeder 305, and as discharge heating molten heat source of the carbon electrode 212, wire 212a, high voltage power supply unit 211, the cover 213 a and the like. Also, it is necessary to readjust the occasion of the environmental gas, and step 3 are the same, and then, also can possess O₂ gas supply bottle 411, an inert gas supply bottle 412, mixed gas supply pipe 420, dehumidifying device 430, dew point thermometer 440, and the like.

As inner layer 56 forming method, first of all will be capable of reducing pressure of the outer frame 101 is set to a predetermined rotation speed, from the high voltage power supply unit 211 gradually load the high-voltage, at the same time to an from the raw material 303 gradually the inner layer 56 of the raw material for forming the inner layer (high-purity silicon dioxide powder) 12 from the base 51 to the upper part of the spray. At this moment, the carbon electrode 212 begins to discharge between, because matrix 51 become the inside of the area of the melting temperature of the silicon dioxide powder (presumed the 1800-2000 [...] left and right), so that the inner layer of the raw material has been sprayed 12 will become molten particles and gradually attached to the base 51 of the inner surface. The base body 51 is provided with an opening at the upper part of the carbon electrode 212, raw material powder inlet, a cover 213, the substrate 51 with a certain degree of position changing mechanism, so that these position changes, and the base 51 is formed on the entire inner surface of uniform thickness of the inner layer 56.

Through this discharge heating melting method of the inner layer 56 the forming process, the oxygen-containing 1-30% and the volume of the inert gas formed by mixing the mixed environment. Also, the dew-point temperature is set to the 10-10 the [...][...] and the setting temperature is controlled in the ± 1 the is in the range of [...] carried out under an air environment.

Specifically, as shown in Figure 10, from O₂ gas supply bottle 411 supply O₂ gas, from the inert gas supply bottle 412 supply the inert gas (for example, nitrogen, argon, or helium), to be mixed and the mixed gas supply pipe 420, and from the base 51 at the inner side of the supply. Furthermore, symbol 510 shown in the arrow showing the outer frame of the flow direction of the mixed gas. At this moment, as described above at the same time capable of reducing pressure the outer frame 101 of the gas in. This ventilation, capable of reducing pressure through the outer frame 101 of the environment gas from the cover 213 discharged to the outside of the gap of the way. Symbol 520 is shown with arrow showing the outer frame of the flow direction of gas ventilated environment.

So, can be silicon dioxide of this invention the container 71, such as the following can be carried out in accordance with the necessary cleaning silicon dioxide container.

(Silicon dioxide container cleaning, drying)

For example, by using a hydrofluoric acid aqueous solution (HF) 1-10% left and right, for surface etching 5-30 minutes, subsequently to the pure water in the clean air washing and the drying, to obtain the silicon dioxide container.

After the above process, such as the above-mentioned, can make on Figure 2 of the present invention shown in a silicon dioxide container 71.

[Embodiment]

The following, embodiments of the present invention said comparison example and more specifically illustrate the invention, but the invention is not limited to these examples.

(Embodiment 1)

In accordance with the as shown in Figure 3 of the present invention of the method of manufacturing silicon dioxide powder and silicon dioxide method of manufacturing container, and in the following manner to manufacture silicon dioxide powder and silicon dioxide container.

First, preparation purity 99.999 weight % and particle size the 50-500   m of natural quartz powder as a raw material for the basal body 11, and is prepared to particle size the 50-500  m, doped with 200 and the weight of the Ba PPM 2 × 10¹⁷ of molecular/g H₂ natural quartz powder as a raw material for the inner layer 12.

Here, the Figure 1 of the process shown, raw material to make the inner layer 12, in order to form silicon dioxide as a container for the inner layer of the raw material powder. Specifically, first of all, preparation purity 99.9999% of the weight of the high purity natural quartz powder. Furthermore, the high purity natural quartz powder is impregnated in the containing 25 weight % barium nitrate Ba (NO₃)₂ in the ethanol alcohol-water solution, and drying the same. Furthermore, the quartz powder inputs into the stainless steel sleeve in the vacuum furnace, the internal environment to 100 volume % of hydrogen, remain 1kgf/cm³ pressure (almost identical to those of a large air pressure) and to the 400 [...] heating 3 hours later, one side of such a hydrogen environment continuously maintained, cooling to room temperature to one side of the 25 [...] , raw material to make the inner layer 12.

Furthermore, if the following manner for the matrix in the raw material powder and the inner layer integrally formed temporarily in an external mold frame. First of all, the inner wall 102 forming a reduced pressure with the hole 103, the rotating cylindrical frame the external mold capable of reducing pressure graphite produced 101 continuously-rotating, raw material for the substrate 11 in the investment mold frame 101 of the inner wall 102 and is adjusted to a predetermined thickness, then inputs raw material for the inner layer 12, and the temporary molded body on the base body 41 on the surface of the inner surface, of the temporary molded body forming the inner layer 46.

Furthermore, from the outside of the outline templet frame , the substrate to vacuum pump the temporary molded body 41 and the inner layer of the temporary molded body 46 to be sustainable pressure reducing, degassing to dew point 7 the the   ± 1 [...] , that is, to control the the 6 [...] to 8 the air in the range of [...] through the carbon electrode discharge heating melting method (arc discharge heating) to carry out two temporary sintering of the molded body, molten.

The manufacturing of the silicon dioxide container 71, in the 3 (HF) weight % aqueous solution of hydrofluoric acid in the 25 under [...] 3 minutes after the washing, the subsequent cleaning and the pure water in the drying.

(Embodiment 2)

With the embodiment 1 the same, but the raw material for the inner layer 12, the Ba doping amount is 500 weight hydrogen PPM and 100% volume, pressure 9.9 kg/cm³ (about 9.9 atmospheric pressure), the 400 [...] heating 3 hours of heating processing the H₂ the doping amount of as 2 × 10¹⁸ molecular/g, thereby manufacturing a silicon dioxide container 71.

(Embodiment 3)

In accordance with fig. 4 in the manufacturing method of the silicon dioxide container (2nd embodiment) for silicon dioxide container 71 manufacturing.

Furthermore, raw material for the basal body 11 and the inner layer with raw material powder 12 production, with the embodiment 1 to the same as.

Also, through the atmospheric pressure the dew point of the 7 the   ± 1 [...] of the arc discharge in the air heating to the base 51 of the sintering, molten, subsequently, from the outer frame 101 is sprayed continuously raw material for the upper part of the inner layer 12 and dew point 7 the the   ± 1 atmospheric [...] arc discharge in the air heating to the inner layer 56 is formed of.

(Embodiment 4)

In accordance with Figure 4 the container shown in the manufacturing method of the silicon dioxide to silicon dioxide container 71 manufacturing.

However, raw material for the basal body 11 and the inner layer with raw material powder 12 production, with the embodiment 2 of the same.

(Embodiment 5)

The embodiment has been carried out 3 almost the same silicon dioxide container of manufacturing. However, raw material for the substrate 11 is doped with a 50 Al PPM of the weight, but also, raw material in the inner layer 12 is added with Ba and H₂, the doped with Al. Also, the base body 51, the inner layer 56 formed of the heating of the environment when the dew-point temperature is set to 3 the the   ± 1 [...].

(Embodiment 6)

With the embodiment 5 is the same, however, with the base 51 and the inner layer 56 is formed of, from the outside of the outer frame to respectively in continuous temporary molded body of the pressure, exhaust, and silicon dioxide to the container 71 manufacturing.

(Embodiment 7)

With the embodiment 5 is the same, but the raw material for the inner layer 12, the Ba doping amount is at least 120 weight PPM. Also, doping with 4 × 10¹⁷ of molecular/g H₂, the silicon dioxide to the container 71 manufacturing.

(Embodiment 8)

With the embodiment 5 is the same, but the raw material for the inner layer 12, the Ba doping amount is 100 weight PPM, the doping amount is Sr 20 weight with the doped PPM 4 × 10¹⁷ of molecular/g H₂, the silicon dioxide to the container 71 manufacturing.

(Comparative example 1)

Probably in accordance with the prior method for manufacturing the container of silicon dioxide (silica crucible). In other words, as a raw material for the basal body, the inner layer with the raw material powder, the particle size is the 50-500  m, purity 99.9999% of the weight of the high purity natural quartz powder. Matrix in the absence of the special humidity adjustment of the arc discharge in the normal temperature in the air heating to form, in the same air of the inner layer from the external mold spraying raw material powder and the upper part of the frame in the normal temperature sustained arc discharge heating to be fused to form.

(Comparative example 2)

With comparative example 1 the same, but the raw material for the inner layer, its Ba doping amount is 500 weight PPM, the silicon dioxide to the manufacturing of the container.

(Comparative example 3)

With comparative example 1 the same, but the raw material for the inner layer, its Ba doping amount is 30 weight PPM, and in the hydrogen 10 volume nitrogen body % and 90% in volume of the mixed gas of the 1kgf/cm³ pressure (about 1 atmospheric pressure), the 400 [...] heating 3 hours of treatment with 2 × 10¹⁶ of molecular/g H₂, the silicon dioxide to the manufacturing of the container.

(Comparative example 4)

With comparative example 1 the same, against, however, for host raw material powder, the purity of 99.99 weight % low purity , the silicon dioxide to the manufacturing of the container.

(Comparative example 5)

With the embodiment 1 the same, but not the inner layer of the raw material of the added hydrogen, the silicon dioxide to the manufacturing of the container.

(Comparative example 6)

With the embodiment 1 the same, but not the inner layer of the raw material powder for the addition of Ba, the silicon dioxide to the manufacturing of the container.

[In the implementation of the example comparison example evaluation method]

In various embodiments used in the comparative example of the raw material powder and gas and of the physical properties of the silicon dioxide container, characteristic evaluation, is carried out as the following.

The method for measuring the particle size of the raw material:

Using an optical microscope or electron microscope to carry out two-dimensional shape of each raw material powder of the observation and area measuring. Furthermore, assuming that the shape of the particle is round, and from its area value in order to calculate the diameter of the obtained. Using a statistical way repeated such modus operandi, as the value of the particle size range (this range contains 99% by weight of the above raw material powder).

Dew point temperature measurement:

Determining according to the dew point temperature.

Furthermore, for each embodiment, such as the above-mentioned, according to the setting of the mixed gas supply pipe 420 of the dew point of the thermometer in 440 are measured.

Metal element impurities concentration analysis:

Impurities are metal element concentration is relatively low the (glass is high-purity), is to use plasma light emitting analysis method (ICP-AES (Inductively   Coupled   Plasma-Atomic   Emission   Spectroscopy): inductively coupled plasma atomic emission spectroscopy), or plasma mass analysis (ICP-MS (Inductively   Coupled   Plasma-Mass   Spectroscopy): induction coupled plasma mass spectrometry) to carry out, impurities are metal element concentration is relatively high (glass is a low-purity) time, is using atomic absorption photometry (AAS (Atomic   Absorption   Spectroscopy): atomic absorption spectroscopy) to carry out.

Layer thickness measurement:

By using the scale to determine the side wall of the container in the silicon dioxide of the total height of the half-parts (height 200 mm part of the) cross section of the container, to determine the thickness of the matrix and inside.

OH-based concentration determination:

The inner layer from the base body and the transparent portion of the samples of the cutting, grinding, and to each to infrared absorption spectrophotometry. Converted to the OH group concentration, is carried out in accordance with the following literature.

"Dodd,   Fraser D.M.and, D.B. (1996 years)   OH   fused Optical   silica.   in   determination   of"   Physics   Applied   of Journal, vol. 37, P.3911 (light judging fused silica of the OH, applied physics journals, section 37 roll, section 3911 page).

Determining the amount of hydrogen emits:

Raw material for the inner layer (as a raw material of the silicon dioxide powder), is such a powder, the inner layer of the container against silicon dioxide hydrogen sundries, the adjustment for the particle diameter of the 100 m-1mm the granular silica glass sample, measured respectively.

Under vacuum the 1000 in [...] , according to the mass analysis device, the inner layer of the raw material from the gas or sample of sundries. Its detailed in accordance with the following literature. Hydrogen H₂ release amount as a whole, and the weight of each unit of the number of emitting molecules (hydrogen/glass g) to performance.

Nasu,   al. S.et (1990 year) "Gas   release   of   various   kinds   of   vitreous   silica; different types of glass silicon dioxide gas discharge",   Engineering   Illuminating Journal   of   Institute   of   Japan, vol. 74, No.9, pp. 595-600 (Japan illuminating engineering Institute journal, section 74 roll, section 9, , section 595-600 page).

Also, the silica glass of the hydrogen gas in the concentration of the dissolved remaining, using 5 mm cube shape grinding the sample, the following documents have been identified using the method for determination of the value of the same can be obtained.

V.S.Khotimchenko, et   al. (1987 years) "Determining   content   of   dissolved   hydrogen   in   the   quartz   glass   of   the   Raman   scattering   methods   using   mass   spectrometry   and; using Raman scattering and mass spectrometry method to judge dissolved in the quartz glass has a hydrogen content in the",   of   Spectroscopy   Applied Journal, vol. 46, No.6, pp. 632-635 (application spectrum journals, section 46 roll, paragraph 6, , section 632-635 page).

Light transmittance determining:

The inner layer, the size of the cut thickness of 5 mm × 5 mm × 11 mm of the glass samples left and right, and is completed the two end portions of the thickness 10 mm parallel optical grinding. Subsequently, according to the mercury lamp as a light source through the rate of visible light, the glass of the sample measured at 600 nm of the linear transmittance (the incident light is set to 100%, and has less to the surface of the sample reflection, the sample internal inside reflection and sample itself absorption of the obtained value, can be referred to as optical transmission (  transmission Optical)). This value reflects the bubble amount in the sample even solubleness and doping elements.

Continuously pulling up silicon single crystal (pulling a plurality of times) evaluation:

In the manufacturing of the silicon dioxide container into the purity is 99.999999% of the weight of metal polycrystalline silicon, and by heating silicon and, subsequently, is repeated 3 times pulling silicon single crystal (pulling a plurality of times), and evaluation of the success rate of the single crystal cultivation. Lifting condition is that the CZ device is set for 10³ Pa pressure of 100% argon (Ar) gas environment, the lifting speed is set to 1 mm/minute, the rotation number 10rpm, and the size of the diameter of the single crystal silicon is 150 mm, length 150 mm. Also, 1 the number of the operation time is about 12 hours. Repeat growing single crystal 3 evaluation of the success rate of classification, such as the following is carried out.

3 successful: O (good)

2 successful: delta (slightly bad)

1 time the following : × (not good)

Evaluation of the cavity or a pinhole:

Pulling the silicon single crystal in a plurality of times, a plurality of times from each of the single crystal silicon of the silicon single crystal pulling after any part of a 2nd, make the diameter 150 mm, thickness 200 the grinding and with double-sided   m of ten sheets of the silicon wafer. Then measuring in of a two-sided of the silicon wafer on the number of the holes or a pinhole, for processing data in a statistical way each unit area obtained (m²) the number of the average cavity or a pinhole.

An average cavity or pinhole few not full 1 a/m²: O (good)

An average cavity or pinhole is 1-2 a/m²: delta (slightly bad)

Average empty in the number of or a pinhole 3 a/m² the above : × (not good)

Silicon dioxide container evaluation of etching resistance:

To 3 times after a plurality of times of pulling up silicon single crystal silicon dioxide container, than silicon dioxide fused surface from the lower part of the silicon dioxide container side wall, the size of the inner wall surface is set to 100 mm × 100 mm manner, so that all of the cut-out has a thickness direction of the thickness of the sample. Furthermore, by using the scale to determine the sample cross-section, and the inner wall segment of the etching amount of the inner layer.

The etched thickness of the inner layer of less than 3 mm:O (good)

Is the etched thickness of the inner layer of 3 mm-less than 5 mm: delta (slightly bad)

The inner layer in the etched thickness of 5 mm or more : × (not good)

Silicon dioxide of the inside of the container to prevent impurities diffusion effect:

From 3 times after a plurality of times of pulling up silicon single crystal of silicon dioxide on the silicon dioxide of the container part melt liquid level , the silica samples of the sidewall of the container as the size of 100 mm × 100 mm × 15 mm (full thickness) and cut-out. Subsequently, the part from the inner surface 100 the aqueous solution (HF)   m layer utilizes the hydrofluoric acid cleaning to remove them. Subsequently, the inner surface of the container the thickness of the part of the 100  m, using 50% hydrofluoric acid aqueous solution (HF) to dissolve the etching processing, and analysis of the etching solution of the alkali metal element concentration value, to thereby evaluate metal element impurities from silicon dioxide purity is low basal body of the inner layer of high purity to the amount of proliferation, is more or less? .

In accordance with the thickness of the inner surface 100 the Li   m part of the, Na, K the total concentration of the classification, is carried out as shown below.

Not full 0.1 wt. ppm   O (good)

0.1 or more-less than 1 wt. ppm   delta (lower)

1 wt .ppm × (difference) above

The manufacturing cost of the silicon dioxide container (relative) evaluation

Evaluation of the manufacturing cost of the silicon dioxide container. In particular raw material expense relative evaluation of silicon dioxide, the total value of molten plurality of resources, and the like. Previous production cost, is in comparative example 1 as a reference.

low ○ cost (not full prior preparation cost 50%)

In cost, delta (previous preparation cost 50% -not full 100%)

Large cost × (the previous production cost is set to 100%)

Finishing embodiment 1-8, comparative example 1-6 of the respective silicon dioxide container and the manufacturing conditions of the processed matter measuring, evaluation results, and display in the following table 1-7 in.

Table 1

Table 2

Table 3

Table 4

Table 5

Table 6

Table 7

From table 1-7, that the silicon dioxide container in accordance with the present invention an embodiment of a method of manufacturing 1-8, although compared with comparative example 1, 2, is the use of low cost and with high productive of the produced silicon dioxide container, the single crystal is, however, also can be used for producing silicon dioxide container, can show not inferior to that of the comparison examples 1, 2 the results of the previous silicon dioxide container.

Therefore, embodiment 1-8 in, can be performed with high success rate a plurality of times of pulling up silicon single crystal, the occurrence of a void or a pinhole can also be in the comparison examples 1, 2 the following the condition, and then, embodiment 1-8 in etching resistance can also be at the same time.

Also, comparison example 3 in, the initial raw material for an inner metal element, there is little concentration of hydrogen, which is not fully etch resistance.

Also, comparison example 4 in, although it can be with low-cost to manufacture silicon dioxide container, however, has a number of holes or a pinhole, low etch resistance, the proliferation of which find many problems.

Also, comparative example 5 in, the inner layer of the raw material powder while the added Ba quantity, but not molecular hydrogen is added, therefore, is still identified as a plurality of holes or a pinhole occurrence.

Also, comparison example 6 in, on the contrary to the inner layer more additive amount of raw material hydrogen, but without the added Ba, therefore, is deemed to be silicon dioxide container of the low etching resistance, inhibit the proliferation of impurities is not full.

Furthermore, the invention is not limited to the above-mentioned embodiment. The above-mentioned embodiment is exemplary, any of the rights of the present invention records the technological thought of the substantially the same form, and reached the mode of execution of the same effect, regardless of the way, are all contained in the technical range of this invention.